JP2016092156A - Deposition device, deposition method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for enhancing the uniformity of thickness in the circumferential direction of the plane of a substrate, when performing deposition while revolving the substrate mounted on a turntable.SOLUTION: A deposition device is constituted to include a rotating mechanism for rotating the placement area of a substrate in a turntable, so that the substrate rotates, a process gas supply mechanism for supplying process gas to a gas supply area on ne side of the turntable, and depositing on the substrate passing through the gas supply area a plurality of times repeatedly by revolution, and a control unit calculating the rotation speed of the substrate based on the parameters including the rotational speed of the turntable, and outputting a control signal so as to rotate the substrate at the rotation speed. Since the processing can be carried out so that the orientation of the substrate changes every time when it is located in the gas supply area, uniformity of thickness can be enhanced in the circumferential direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a film forming apparatus, a film forming method, and a storage medium for obtaining a thin film by supplying a processing gas to a substrate.

  As a technique for forming a thin film such as silicon oxide (SiO 2) on a substrate such as a semiconductor wafer (hereinafter referred to as “wafer”), for example, a film forming apparatus that performs ALD (Atomic Layer Deposition) is known. As an example of this film forming apparatus, there is an apparatus in which a rotary table on which, for example, a wafer is placed is provided in a processing container whose inside is a vacuum atmosphere. On the turntable, for example, a gas nozzle that discharges a source gas that is a raw material of a silicon oxide film and a gas nozzle that discharges an oxidizing gas that oxidizes the source gas are arranged. Then, the wafer is revolved by the rotation of the rotary table, and the silicon oxide film is formed by alternately passing the wafer through the adsorption region to which the source gas is supplied and the oxidation region to which the oxidizing gas is supplied. .

  In order to control the film thickness distribution in the plane of the wafer in the ALD, it is necessary to control the distribution of the source gas adsorbed on the wafer. Therefore, in the film forming apparatus, the source gas gas nozzle is controlled. Adjustment about the number and position of the discharge outlet provided is performed suitably. Furthermore, selection of the shape of the gas nozzle, adjustment of the supply amount of the separation gas supplied to partition the adsorption region and the oxidation region, adjustment of the concentration of the carrier gas in the raw material gas, and the like are also performed as appropriate.

  By the way, there are cases where the respective etching rates can be adjusted for the peripheral portion and the central portion of the wafer by an etching process performed after the film forming process. In that case, since the film thickness can be made uniform at the peripheral part and the central part after etching, it is required to obtain a highly uniform film thickness particularly in the circumferential direction of the wafer. However, due to the above revolution, each part of the wafer repeatedly moves on the same trajectory at a predetermined distance from the rotation center of the rotary table. Therefore, the variation in the distribution of the raw material gas in the adsorption region may appear as a variation in the film thickness when viewed along the radial direction of the rotary table on the wafer. Then, there was a possibility that this variation in film thickness could not be solved sufficiently.

  Patent Document 1 describes a film forming apparatus in which a wafer revolves in this way, and in order to improve the film thickness uniformity in the circumferential direction, the rotating table rotates when stopped in a predetermined direction. A mechanism is provided in which the wafer placed on the table is lifted off the rotary table, changed in direction, and placed on the rotary table again. However, according to the film forming apparatus of Patent Document 1, the rotation table is stopped every time the orientation of the wafer is changed, and thus there is a risk that throughput may be reduced.

  Also, Patent Document 2 describes a film forming apparatus in which a wafer revolves. In this film forming apparatus, it is described that a wafer placed on the rotary table rotates while the rotary table rotates. . However, it is not described what rotation speed is set for the rotation of the wafer. If the rotation speed of the rotation of the wafer is not set appropriately, the rotation and revolution of the wafer are synchronized. That is, when the wafer passes through the adsorption region, it passes in the same direction, and the film thickness uniformity in the circumferential direction of the wafer may not be sufficiently improved.

Patent 5093162 Patent 4817210

  The present invention has been made under such circumstances, and its purpose is to make the film thickness uniform in the circumferential direction in the plane of the substrate when the substrate placed on the turntable is revolved to form a film. It is to provide a technology that can enhance the performance.

The film forming apparatus of the present invention
A film forming apparatus for obtaining a thin film by supplying a processing gas to a substrate,
A rotary table that is placed in a vacuum vessel and placed on a placement area provided on one side thereof to revolve the substrate,
A rotation mechanism for rotating the placement area so that the substrate rotates,
A process gas supply mechanism for supplying the process gas to a gas supply region on one surface side of the turntable and performing film formation on the substrate that repeatedly passes through the gas supply region by the revolution; and
The rotation speed of the substrate is calculated based on parameters including the rotation speed of the turntable so that the orientation of the substrate changes every time the substrate is positioned in the gas supply region, and the substrate is moved at the calculated rotation speed. A control unit that outputs a control signal so as to rotate,
It is provided with.

The film forming method of the present invention comprises:
A film forming method for obtaining a thin film by supplying a processing gas to a substrate,
A step of placing and revolving a substrate on a placement region provided on one side of a rotary table disposed in a vacuum vessel;
Rotating the mounting region so that the substrate rotates by a rotation mechanism;
Supplying the processing gas to a gas supply region on one surface side of the turntable by a processing gas supply mechanism, and forming a film on a substrate that repeatedly passes through the gas supply region;
Calculating the rotation speed of the substrate based on parameters including the rotation speed of the turntable so that the orientation of the substrate changes each time the substrate is positioned in the gas supply region;
A process of rotating the substrate at the calculated rotation speed;
It is provided with.
The storage medium of the present invention is a storage medium storing a computer program used in a film forming apparatus for obtaining a thin film by supplying a processing gas to a substrate.
The computer program is characterized in that steps are set so as to implement the film forming method.

  According to the present invention, the rotation speed of the substrate is calculated based on parameters including the rotation speed of the rotary table, and the substrate is rotated at the calculated rotation speed. Thereby, every time the substrate is positioned in the gas supply region on the rotary table, the direction of the substrate can be reliably changed. Therefore, the film can be formed with a highly uniform film thickness in the circumferential direction of the substrate.

It is a vertical side view of the film-forming apparatus which concerns on this invention. It is a cross-sectional top view of the said film-forming apparatus. It is a perspective view which shows the inside of the said film-forming apparatus. It is a surface side perspective view of the turntable of the said film-forming apparatus. It is a back surface side perspective view of the said rotation table. It is a block diagram of the control part which comprises the control part provided in the said film-forming apparatus. It is explanatory drawing which shows the position and orientation of a wafer at the time of a film-forming process. It is explanatory drawing which shows the position and orientation of a wafer at the time of a film-forming process. It is explanatory drawing which shows the position and orientation of a wafer at the time of a film-forming process. It is explanatory drawing which shows the position and orientation of a wafer at the time of a film-forming process. It is explanatory drawing which shows the flow of the gas on the said rotary table at the time of the said film-forming process. It is a vertical side view which shows the structural example of the wafer holder provided in the said rotation table. It is a vertical side view which shows the structural example of the vacuum vessel of the said film-forming apparatus. It is a vertical side view of the film-forming apparatus which concerns on other embodiment of this invention. It is a surface side perspective view of the turntable of the said film-forming apparatus. It is a schematic diagram which shows rotation of the wafer mounted on the rotary table. It is a schematic diagram which shows rotation of the wafer mounted on the rotary table. It is a schematic diagram which shows rotation of the wafer mounted on the rotary table. It is a surface side perspective view which shows the structure of the rotary table of another film-forming apparatus. It is a schematic diagram which shows the film thickness distribution of the wafer in an evaluation test. It is a schematic diagram which shows the film thickness distribution of the wafer in an evaluation test. It is a graph which shows the film thickness distribution of the wafer in an evaluation test. It is a graph which shows the film thickness distribution of the wafer in an evaluation test. It is a schematic diagram which shows the film thickness distribution of the wafer in an evaluation test. It is a schematic diagram which shows the film thickness distribution of the wafer in an evaluation test. It is a graph which shows the film thickness distribution of the wafer in an evaluation test. It is a graph which shows the film thickness distribution of the wafer in an evaluation test. It is a schematic diagram which shows the film thickness distribution of the wafer in an evaluation test. It is a schematic diagram which shows the film thickness distribution of the wafer in an evaluation test. It is a graph which shows the film thickness distribution of the wafer in an evaluation test.

  A film forming apparatus 1 that performs ALD on a wafer W as a substrate, which is an embodiment of the vacuum processing apparatus of the present invention, will be described. The film forming apparatus 1 adsorbs BTBAS (bistar butylaminosilane) gas as a source gas, which is a processing gas containing Si (silicon), on the wafer W, and ozone (O 3), which is an oxidizing gas that oxidizes the adsorbed BTBAS gas. ) A gas is supplied to form a molecular layer of SiO2 (silicon oxide), and the molecular layer is exposed to plasma generated from a plasma generating gas in order to modify the molecular layer. This series of processes is repeated a plurality of times to form an SiO2 film.

  FIG. 1 and FIG. 2 are a longitudinal side view and a transverse plan view of the film forming apparatus 1. The film forming apparatus 1 includes a substantially circular flat vacuum container (processing container) 11 and a disk-shaped horizontal rotary table (susceptor) 2 provided in the vacuum container 11. The vacuum container 11 includes a top plate 12 and a container body 13 that forms the side wall and bottom of the vacuum container 11.

  A central shaft 21 that extends vertically downward from the center of the turntable 2 is provided. The central shaft 21 is connected to a revolving rotation drive unit 22 provided so as to close the opening 14 formed at the bottom of the container body 13. The turntable 2 is supported in the vacuum vessel 11 via the center shaft 21 and the revolution rotation drive unit 22 and rotates clockwise in plan view. In FIG. 1, reference numeral 15 denotes a gas nozzle that discharges N2 (nitrogen) gas into the gap between the central shaft 21 and the container main body 13, and N2 gas is discharged during processing of the wafer W to move from the front surface to the back surface of the turntable 2. It has a role to prevent wraparound of raw material gas and oxidizing gas.

  Further, on the lower surface of the top plate 12 of the vacuum vessel 11, a center region forming portion C having a circular shape in plan view protruding so as to face the center portion of the turntable 2, and from the center region forming portion C to the outside of the turntable 2. Projection portions 17 and 17 having a fan-like shape in plan view and formed so as to spread toward the top are formed. That is, the central region forming portion C and the protruding portions 17 and 17 constitute a lower ceiling surface than the outer region. The gap between the central region forming part C and the central part of the turntable 2 constitutes the N2 gas flow path 18. During processing of the wafer W, N 2 gas is supplied from the gas supply pipe connected to the top plate 12 to the flow path 18, and is discharged from the flow path 18 toward the entire outer periphery of the turntable 2. This N 2 gas prevents the source gas and the oxidizing gas from coming into contact with each other on the center portion of the turntable 2.

  FIG. 3 is a perspective view showing a bottom surface inside the container body 13. A flat ring-shaped recess 31 is formed in the container main body 13 along the circumference of the turntable 2 below the turntable 2. A ring-shaped slit 32 is formed in the bottom surface of the recess 31 along the circumferential direction of the recess 31, and the slit 32 is formed so as to penetrate the bottom of the container body 13 in the thickness direction. ing. Further, on the bottom surface of the recess 31, a heater 33 for heating the wafer W placed on the turntable 2 is arranged in seven rings. In FIG. 3, in order to avoid complication, a part of the heater 33 is cut out.

  The heaters 33 are arranged along concentric circles centering on the rotation center of the turntable 2, and four of the seven heaters 33 are inside the slit 32 and the other three are outside the slit 32. Is provided. Moreover, the shield 34 is provided so that the upper side of each heater 33 may be covered and the upper side of the recessed part 31 may be plugged up (refer FIG. 1). The shield 34 is provided with a ring-shaped slit 37 so as to overlap the slit 32, and a rotating shaft 32 and a column 41 described later penetrate the slit 37. Further, exhaust ports 35 and 36 for exhausting the inside of the vacuum container 11 are opened outside the recess 31 on the bottom surface of the container body 13. An exhaust mechanism (not shown) configured by a vacuum pump or the like is connected to the exhaust ports 35 and 36.

  Next, the turntable 2 will be described with reference to FIGS. 4 and 5 showing the front side and the back side, respectively. On the front surface side (one surface side) of the turntable 2, five circular recesses are formed along the rotation direction of the turntable 2, and a circular wafer holder 24 is provided in each recess. A recess 25 is formed on the surface of the wafer holder 24, and the wafer W is horizontally stored in the recess 25. Therefore, the bottom surface of the recess 25 constitutes a placement area on which the wafer is placed. In this example, the height of the side wall of the recess 25 is the same as the thickness of the wafer W, for example, 1 mm.

  For example, three struts 41 are extended vertically downward from positions separated from each other in the circumferential direction of the back surface of the turntable 2, and the lower ends of the respective struts 41 are formed through slits 32 as shown in FIG. The bottom of the container body 13 is penetrated and connected to a support ring 42 which is a connection part provided below the container body 13. The support ring 42 is formed along the rotation direction of the turntable 2, is provided horizontally so as to be suspended from the container body 13 by the support column 41, and rotates together with the turntable 2.

  A rotation shaft 26 that is a rotation shaft for rotation extends vertically downward from the lower center portion of the wafer holder 24. The lower end of the rotary shaft 26 passes through the rotary table 2, passes through the bottom of the container body 13 through the slit 32 as shown in FIG. 1, and is further provided on the support ring 42 and below the support ring 42. The magnetic seal unit 20 is connected to the rotation drive unit 27 for rotation. The magnetic seal unit 20 includes a bearing for rotatably supporting the rotating shaft 26 with respect to the support ring 42 and a magnetic seal (magnetic fluid seal) for sealing a gap around the rotating shaft 26.

  The magnetic seal is provided so that particles generated from the bearing, for example, lubricating oil used for the bearing can be prevented from diffusing into a vacuum atmosphere outside the magnetic seal unit 20. Further, since the rotating shaft 26 is supported by the bearing, the wafer holder 24 is slightly lifted from the rotating table 2, for example. The rotation driving unit 27 for rotation includes a motor, and is provided below the support ring 42 so as to be supported by the support ring 42 via the magnetic seal unit 20, and the rotation shaft 26 is pivoted by the motor. Rotate around. As the rotation shaft 26 is supported and rotated in this way, the wafer holder 24 is rotated, for example, counterclockwise in plan view.

  The rotation of the turntable 2 rotates (revolves) the wafer W around the center axis of the turntable 2, and the rotation of the wafer holder 24 rotates the wafer W around the center. The rotation of the wafer W around the center of the wafer W may be described as the rotation of the wafer W. In the film forming apparatus 1, these revolutions and rotations are performed in parallel with each other during film formation on the wafer W. The rotation of the wafer W includes not only the case where the wafer W is continuously rotated around the center thereof but also the intermittent rotation of the wafer W around the center thereof. In the case of rotating intermittently, the rotation of the wafer W is stopped before rotating around the center one or more times, and then the rotation of the wafer W is restarted.

  In the figure, 44 is a shield ring provided so as to overlap the support ring 42, and in FIGS. 4 and 5, it is indicated by a chain line in order to prevent complication of the drawing. As shown in FIG. 1, the shield ring 44 is provided so as to close the slit 16 of the container body 13 from the lower side of the container body 13, and is configured to rotate together with the turntable 2. Therefore, the rotary shaft 26 and the support column 41 are provided so as to penetrate the shield ring 44. The shield ring 44 serves as a heat shield for preventing the rotation driving unit 27 for rotation from being exposed to each gas and being excessively heated.

Further, as shown in FIG. 1, a lower wall portion 45 that is formed in a concave shape in a cross-sectional view and surrounds the support ring 42, the rotation drive unit 27 for rotation, and the shield ring 44 is provided below the container body 13. It is formed in a ring shape along the direction. Further, five charging mechanisms 46 (only one is shown in FIG. 1) are provided at the bottom of the lower wall portion 45 so as to be separated from each other in the circumferential direction. When processing is not performed on the wafer W, the rotary table 2 is stationary so that the rotation drive unit 27 for rotation is located immediately below the charging mechanism 46, and each rotation drive unit for rotation by non-contact power supply from the charging mechanism 46. Each charging mechanism 46 is arranged so that 27 can be charged. In the figure, reference numeral 47 denotes a gas supply path that opens into a space surrounded by the lower wall portion 45. In the figure, 48 is a gas nozzle, and N ₂ gas is supplied to the space surrounded by the lower wall portion 45 through the gas supply path 47, for example, during the processing of the wafer W, and the space is purged. Although not shown in FIG. 1, for example, the space communicates with an exhaust passage that connects the exhaust ports 36 and 37 and the exhaust mechanism (not shown) as will be described later by way of example. Even if particles are generated, they are purged and removed to the exhaust passage by the N ₂ gas.

  A transfer port 37 for the wafer W and a gate valve 38 for opening and closing the transfer port 37 are provided on the side wall of the container body 13 (see FIG. 2), and a transfer mechanism that enters the vacuum vessel 11 through the transfer port 37. The wafer W is transferred between the recess 25 and the recess 25. Specifically, through holes are formed at positions corresponding to each other on the bottom surface of the recess 25, the bottom of the container body 13 and the turntable 2, and the tip of the pin is located on the recess 25 and the container body via each through hole. 13 is configured to move up and down. The wafer W is transferred via these pins. The illustration of this pin and the through hole of each part through which the pin penetrates is omitted.

  As shown in FIG. 2, on the turntable 2, the source gas nozzle 51, the separation gas nozzle 52, the oxidizing gas nozzle 53, the plasma generating gas nozzle 54, and the separation gas nozzle 55 are spaced in this order in the rotation direction of the turntable 2. Arranged. Each gas nozzle 51 to 55 is formed in a bar shape extending horizontally along the diameter of the turntable 2 from the side wall of the vacuum vessel 11 toward the center, and gas is discharged from a number of discharge ports 56 formed along the diameter. Is discharged downward.

  A raw material gas nozzle 51 that forms a processing gas supply mechanism discharges the above-described BTBAS (Bistal Butylaminosilane) gas. In the figure, reference numeral 57 denotes a nozzle cover that covers the source gas nozzle 51 and is formed in a fan shape that spreads from the source gas nozzle 51 toward the upstream side and the downstream side in the rotation direction of the turntable 2. The nozzle cover 57 has a role of increasing the concentration of the BTBAS gas below the nozzle cover 57 to increase the adsorption property of the BTBAS gas to the wafer W. The oxidizing gas nozzle 53 discharges the ozone gas. The separation gas nozzles 52 and 55 are gas nozzles that discharge N 2 gas, and are arranged so as to divide the fan-shaped protrusions 17 and 17 of the top plate 12 in the circumferential direction.

  The plasma generating gas nozzle 54 discharges a plasma generating gas made of, for example, a mixed gas of argon (Ar) gas and oxygen (O 2) gas. The top plate 12 is provided with a fan-shaped opening along the direction of rotation of the turntable 2, and a cup shape made of a dielectric material such as quartz corresponding to the shape of the opening so as to close the opening. The plasma forming part 61 is provided. The plasma forming unit 61 is provided between the oxidizing gas nozzle 53 and the protruding portion 14 when viewed in the rotation direction of the turntable 2. In FIG. 2, the position where the plasma forming unit 61 is provided is indicated by a chain line.

  A protrusion 62 is provided on the lower surface of the plasma forming part 61 along the peripheral edge of the plasma forming part 61, and the tip of the plasma generating gas nozzle 54 is surrounded by the protrusion 62. The protrusion 62 is penetrated from the outer peripheral side of the turntable 2 so that gas can be discharged to the region. The protruding portion 62 has a role of suppressing the entry of N 2 gas, ozone gas, and BTBAS gas below the plasma forming portion 61 and suppressing a decrease in the concentration of the plasma generating gas.

  A depression is formed on the upper side of the plasma forming portion 61, and a box-shaped Faraday shield 63 that opens upward is disposed in the depression. On the bottom surface of the Faraday shield 63, an antenna 65 in which a metal wire is wound around a vertical axis in a coil shape is provided via an insulating plate member 64. A high frequency power supply 66 is connected to the antenna 65. ing. The bottom surface of the Faraday shield 63 has a slit 67 for preventing the electric field component from moving downward in the electromagnetic field generated in the antenna 65 when a high frequency is applied to the antenna 65 and for directing the magnetic field component downward. Is formed. The slits 67 extend in a direction perpendicular to (intersect) the winding direction of the antenna 65, and a large number of slits 67 are formed along the winding direction of the antenna 65. By configuring each unit in this manner, when the high frequency power supply 66 is turned on and a high frequency is applied to the antenna 65, the plasma generating gas supplied below the plasma forming unit 61 can be turned into plasma.

  On the turntable 2, the lower region of the nozzle cover 57 of the source gas nozzle 51 is an adsorption region R1 where the BTBAS gas as the source gas is adsorbed, and the lower region of the oxidizing gas nozzle 53 is oxidized by the BTBAS gas with ozone gas. This is referred to as oxidized region R2. Further, the lower region of the plasma forming unit 61 is a plasma forming region R3 in which the SiO2 film is modified by plasma. The lower region of the protrusions 17 and 17 is separated to separate the adsorption region R1 and the oxidation region R2 from each other by the N2 gas discharged from the separation gas nozzles 52 and 55 to prevent mixing of the source gas and the oxidation gas. Regions D and D are configured, respectively.

  The exhaust port 35 is opened to the outside between the adsorption region R1 and the separation region D adjacent to the adsorption region R1 on the downstream side in the rotation direction, and exhausts excess BTBAS gas. The exhaust port 36 is opened outside the vicinity of the boundary between the plasma formation region R3 and the separation region D adjacent to the plasma formation region R3 on the downstream side in the rotation direction, and is used for generating excess O3 gas and plasma. Exhaust the gas. From each exhaust port 35, 36, N 2 gas supplied from each separation region D, the gas supply pipe 15 below the turntable 2, and the center region forming portion C of the turntable 2 is also exhausted.

  The film forming apparatus 1 is provided with a control unit 100 including a computer for controlling the operation of the entire apparatus (see FIG. 1). The control unit 100 stores a program for executing a film forming process as will be described later. The program controls the operation of each unit by transmitting a control signal to each unit of the film forming apparatus 1. Specifically, the amount of gas supplied from each of the gas nozzles 51 to 56, the temperature of the wafer W by the heater 33, the amount of N2 gas supplied from the gas supply pipe 15 and the center region forming unit C, and the rotation by the revolution rotation drive unit 22 The rotation speed of the table 2, the rotation speed of the wafer holder 24 by the rotation driving unit 27 for rotation, and the like are controlled according to the control signal. In the above program, these controls are performed, and a group of steps is set so that each process described later is executed. The program is installed in the control unit 100 from a storage medium such as a hard disk, a compact disk, a magneto-optical disk, a memory card, or a flexible disk.

  In the film forming apparatus 1, the wafer W is revolved and processed by rotating the turntable 2. As described above, the rotation of the wafer W by the rotation of the wafer holder 24 is performed in parallel with the rotation of the rotation table 2, but the rotation of the rotation table 2 and the rotation of the wafer holder 24 are not synchronized. More specifically, when the turntable 2 rotates once from a state in which the first direction is directed to a predetermined position in the vacuum vessel 11 and is again positioned at the predetermined position, the wafer W is set to the first direction. The wafer W rotates at a rotation speed (rotation speed) that is directed in a different second direction. The rotation speed A (unit: rpm) of the wafer W is set by the controller 100 based on parameters input by the operator.

  The description will be continued with reference to FIG. 6, which is a block diagram of the control unit 100. The control unit 100 includes a setting unit 101 including an operation panel provided with buttons or the like for an operator to input and set parameters, a memory 102 storing a plurality of processing recipes, and a cycle rate R (unit: nm). / Times) is stored. The processing recipe includes, for example, a target film thickness T (unit: nm) of the SiO 2 film formed on the wafer W, a flow rate of gas supplied from each part of the film forming apparatus 1, and a rotation speed V (unit: rpm) of the turntable 2. ) And data associated with each other. The cycle rate R is the amount of increase in film thickness every time one ALD cycle consisting of the above-mentioned supply of raw material gas, supply of oxidizing gas, and modification by plasma is carried out. The amount of increase in the film thickness per unit.

  The control unit 100 is provided with a work memory 104 and a display unit 105. In the work memory 104, various parameters are input from the memories 102 and 103, and the rotation speed of the wafer holder 24 is calculated based on the parameters. The display unit 105 displays the calculation result in the work memory 104.

  When the operator performs a predetermined operation from the setting unit 101, one of the plurality of processing recipes is selected, and the target film thickness T and the rotation speed V of the turntable 2 included in the processing recipe selected from the memory 102 are Read to work memory 104. Further, when the operator performs a predetermined operation from the setting unit 101, the cycle rate R is read from the memory 103 to the work memory 104.

  In the work memory 104, from the read target film thickness T and cycle rate R, the number of rotations T / R = M at which the turntable 2 rotates from the start of the film formation process to the end of the film formation process is calculated. Is done. The time of starting the film forming process is a time point when the rotation of the turntable 2 and the supply of gas from the source gas nozzle 51 are both performed. The end of the film forming process is a time when at least one of the rotation of the turntable 2 and the supply of gas from the source gas nozzle 51 stops. The calculated number M of rotations of the rotary table 2 is displayed on the display unit 105. Based on this display, the operator sets the number of rotations N (N = natural number) of the wafer holder 24 from the setting unit 101. The number N of rotations is the number of rotations of the wafer holder 24 from the start of the film formation process to the end of the film formation process.

  As the number of rotations N, a value different from a value that is an integral multiple of the number of rotations M of the turntable 2 is set. The reason for this setting is to prevent synchronization between the rotation of the turntable 2 and the rotation of the wafer W. It is preferable to set an integer of 1 or more as N. The reason for this is that the wafer W passes through the raw material gas adsorption region R1 in various directions by the above-mentioned rotation and revolution, but the number of times of passing in each direction is made uniform, and the film in the circumferential direction of the wafer W is This is to increase the uniformity of the thickness distribution.

  When the number N of rotations is set, the rotation speed A (rpm) of the wafer W is calculated from the number N of rotations, the rotation speed V of the turntable 2, and the number of rotations of the turntable 2. Specifically, the rotation speed A (rpm) of the wafer = the rotation speed V (rpm) of the turntable 2 × 1 / M (times) × N is calculated, and the calculation result is displayed on the screen 105. Further, when the rotation speed A is calculated, for example, it is determined whether or not the rotation speed of the wafer W is equal to or less than a reference value, for example, 10 rpm or less. If it is determined that the rotation speed A is equal to or less than the reference value, processing is possible. A message to that effect is displayed on the screen 105, and a film forming process can be started by performing a predetermined operation from the setting unit 101. If it is determined that the reference value is exceeded, for example, the screen 105 displays that each parameter needs to be reset.

  When the rotation speed A of the wafer W is higher, the orientation of the wafer W changes greatly while passing through the adsorption region R1, so that the film in the circumferential direction of the wafer W is independent of the distribution of the source gas in the adsorption region R1. Although the uniformity of the thickness distribution can be increased, if the rotation speed A of the wafer W is too high, the wafer W is lifted from the wafer holder 24 by the centrifugal force and easily detached. For this reason, the rotation speed A of the wafer W is preferably limited to be equal to or less than the reference value.

  The calculation of the rotation speed A (rpm) of the wafer W will be described with a specific example. For example, it is assumed that the target film thickness T and the rotation speed V of the turntable 2 in the selected processing recipe are 32 nm and 60 rpm, respectively, and the cycle rate R is 0.095 nm / time. In the work memory 104, the number of rotations of the rotary table is calculated as M = T / R = 32 (nm) /0.095 (nm / time) ≈337 times. When the number of rotations N (times) of the wafer W is set, the rotation speed A (rpm) of the wafer W = V (rpm) × 1 / M (times) × N = 60 × 1/337 × N≈0. Calculated as 178 rpm. Since the number of rotations M of the turntable 2 is 337, a natural number other than 337 is set as the number of rotations N to prevent synchronization as described above. In addition, each said calculation and determination are performed by the program of the control part 100. FIG.

  A film forming process on the wafer W by the film forming apparatus 1 will be described. As described with reference to FIG. 6, the processing recipe is selected, the target film thickness T and the rotation speed of the turntable 2 are set, the cycle rate R is read, and the number of rotations N is set. Set for speed. Then, the wafer W is placed on each wafer holder 24 by a transfer mechanism (not shown) (FIG. 7). Hereinafter, description will be made with reference to FIGS. 7 to 10 schematically showing the wafer W placed on the turntable 2. 7 to 10, the wafers W are shown as W1 to W5 for convenience of illustration. Further, in order to indicate the direction of the wafer W that is displaced during the film forming process, the arrows directed to the center of the turntable 2 in the region that matches the diameter of the turntable 2 with respect to the diameters of the wafers W1 to W5 before the film forming process. A1 to A5 are attached.

  After placing the wafers W1 to W5, the gate valve 38 is closed, and the vacuum chamber 11 is evacuated to a predetermined pressure by the exhaust from the exhaust ports 35 and 36, and the N2 gas is supplied from the separation gas nozzles 52 and 55 to the rotary table. 2 is supplied. Further, N 2 gas is supplied as a purge gas from the central region forming part C of the turntable 2 and the gas supply pipe 15 below the turntable 2 and flows from the center side of the turntable 2 to the peripheral side. Further, the temperature of the heater 33 rises, the rotary table 2 and the wafer holder 24 are heated by the radiant heat from the heater 33, and the wafers W <b> 1 to W <b> 5 are heated to a predetermined temperature by the heat transfer from the wafer holder 24.

  Thereafter, the rotation of the turntable 2 at the rotation speed V set by the operator and the rotation of the wafer holder 24 at the calculated rotation speed A of the wafer W are both started. That is, the revolution and rotation of the wafer W are started. For example, simultaneously with the start of these revolutions and rotations, the supply of each gas from the source gas nozzle 51, the oxidizing gas nozzle 53, and the plasma generating gas nozzle 54 and the formation of plasma by applying a high frequency from the high frequency power source 66 to the antenna 65 are started. Is done. Each gas is supplied at a flow rate according to the selected processing recipe. FIG. 8 shows a state in which the time has elapsed since the start of film formation, the rotary table 2 is rotated 180 ° from the start of film formation, and the orientation of the wafer W is changed by the rotation.

  FIG. 11 shows the flow of each gas in the vacuum vessel 11 with arrows. Since the separation region D to which the N2 gas is supplied is provided between the adsorption region R1 and the oxidation region R2, the source gas supplied to the adsorption region R1 and the oxidation gas supplied to the oxidation region R2 are the turntable 2 The exhaust gas is exhausted from the exhaust port 35 together with the N2 gas without being mixed with each other. Further, since the separation region D to which N2 gas is supplied is also provided between the adsorption region R1 and the plasma formation region R3, the source gas, the plasma generating gas and the plasma formation region to be supplied to the plasma formation region R3 are provided. The oxidizing gas from the upstream side in the rotation direction of R3 toward the separation region D is exhausted from the exhaust port 36 together with the N2 gas without being mixed with each other on the rotary table 2. The N 2 gas supplied from the central region forming part C and the gas supply pipe 15 is also removed from the exhaust ports 35 and 36.

With the supply and exhaust of each gas as described above, the wafers W1 to W5 rotate while rotating while the adsorption region R1 below the nozzle cover 57 of the source gas nozzle 51 and the oxidation region R2 below the oxidation gas nozzle 53. The plasma forming region R3 below the plasma forming unit 61 is repeatedly moved in order. In the adsorption region R1, the BTBAS gas discharged from the source gas nozzle 51 is adsorbed by the wafer W, and in the oxidation region R2, the adsorbed BTBAS gas is oxidized by the O ₃ gas supplied from the oxidation gas nozzle 53, and molecules of silicon oxide are obtained. One or more layers are formed. In the plasma formation region R3, the molecular layer of silicon oxide is exposed to plasma and modified.

  As described above, the wafer holder 24 rotates without being synchronized with the rotation of the turntable 2, and each wafer W1 to W5 is directed in a different direction each time it is located at a predetermined position in the suction region R1. FIG. 9 shows a state where the turntable 2 has made one rotation since the start of the film forming process. FIG. 10 shows a state in which the rotation of the turntable 2 is further continued from the state shown in FIG. 9 and the direction of the wafers W1 to W5 is directed to the direction rotated 180 ° from the direction at the start of the film forming process. Show. As the orientation of the wafers W1 to W5 changes in this way, each part in the circumferential direction of the wafer W passes through different positions in the suction region R1. Therefore, even if the concentration distribution of the source gas varies at each position in the adsorption region R1, the amount of the source gas adsorbed on the wafer W from the start of the film formation process to the end of the film formation process is determined. Aligned at each part in the direction. As a result, it is possible to suppress the uneven thickness of the SiO 2 film formed on the wafer W at each portion in the circumferential direction of the wafer W.

  In this way, the rotation of the turntable 2 is continued and the silicon oxide molecular layers are sequentially stacked to form the silicon oxide film and the film thickness gradually increases. When the film forming process is performed so as to obtain the set target film thickness, that is, when the turntable 2 is rotated by the number of times calculated based on the set parameters, the rotation of the turntable 2 and the wafer holder 24 are rotated. Rotation stops, and the film forming process ends. At the end of the film forming process, the wafers W1 to W5 are located at the same position as when the film forming process is started, and the wafer rotation number N is set as an integer as described with reference to FIG. Is directed in the same direction as at the start of the film forming process. Accordingly, the wafers W1 to W5 are placed at the positions and orientations shown in FIG. At the end of the film forming process, the supply of each gas from the gas nozzle 51 to the gas nozzle 55 and the formation of plasma are also stopped. Thereafter, the wafers W1 to W5 are unloaded from the vacuum container 11 by the transfer mechanism.

  In the film forming apparatus 1, the rotation speed V of the turntable 2, the target film thickness T of SiO 2, the cycle rate R, and the number of rotations N of the wafer W are set as parameters, and suction is performed based on the set parameters. Each time the wafer W is positioned in the region R1, the rotation speed A of the wafer W is calculated so as to face different directions, and the wafer W rotates at the rotation speed A. Accordingly, the uniformity of the SiO 2 film thickness in the circumferential direction of the wafer W can be increased.

  In the film forming apparatus 1, the operator can freely set the number of rotations N as described above. The smaller the number N of rotations, the smaller the change in orientation from when the wafer W is positioned in the suction region R1 until it is next positioned in the suction region R1. That is, the degree of dispersion of the orientation of the wafer W when it is positioned in the suction region R1 by the end of the film forming process is increased. That is, the film forming apparatus 1 has an advantage that the degree of dispersion in this direction can be set easily and reliably. As an example of setting N, the number of times that the wafer W passes through the suction region R1 in each direction is made uniform by setting an integer as described above, and the uniformity of the film thickness in the circumferential direction is more reliably increased. Can do. The number N of rotations of the wafer is preferably an integer as described above. However, even if a number including a decimal number is set, the deviation of the film thickness distribution in the circumferential direction can be reduced. One or more natural numbers including may be set.

  In addition, according to the film forming apparatus 1, the rotary shaft 26 for supporting the wafer holder 24 is supported by the support ring 42 supported by the rotary table 2 via the support column 41. The heaters 33 are arranged on the inner side and the outer side of the moving path of the support column 41 and the rotary shaft 26, respectively. With such a configuration, the heater 33 can heat the wafer W via the turntable 2 without hindering the movement of the support column 41 and the rotation shaft 26.

In the above example, the rotation speed V of the turntable 2, the target film thickness T of SiO2, and the cycle rate R are read from the memories 102 and 103 to the work memory 104, but at least one of these parameters is By inputting from the setting unit 101 by an operator, the rotation speed A of the wafer W may be calculated by being input to the work memory 104.
Further, for example, the operator can set the rotation speed V of the turntable 2 and the ratio K for determining the rotation speed A of the wafer W by multiplying V from the setting unit 101. A = V × K may be calculated, and the rotation speed A of the wafer W may be set. As the ratio K, a numerical value is set such that the rotation of the wafer W is asynchronous with the revolution of the wafer W, for example, K = 0.1, 0.2, 0.3... 1.1, 1.2. It is selected from numerical values such as 1.3.

  Incidentally, as shown in FIG. 12, in the film forming apparatus 1 described above, the height H1 of the side wall of the recess 25 of the wafer holder 24, that is, the depth of the recess 25 may be formed larger than the thickness H2 of the wafer W. . In this example, H1 is 1.8 times H2, H1 is 1.8 mm, and H2 is 1 mm. Explaining the reason for such a configuration, as shown in FIG. 9, the N 2 gas discharged from the central region forming portion C and the separation gas nozzles 52 and 55 flows laterally on the surface of the turntable 2 and is exhausted. Is done. In FIG. 12, among these N 2 gases, the N 2 gas supplied from the central region forming portion C is shown by arrows. Since H1> H2 as described above, a step is formed between the top of the sidewall of the recess 25 and the peripheral edge of the wafer W surface. Outside the adsorption region R1, the N2 gas flowing in the lateral direction above the recess 25 stagnates at a step on the upstream side in the direction in which the N2 gas flows in the recess 25, as shown in FIGS. A thick part is formed. That is, the gas reservoir 71 is formed at the step.

  When the concave portion 25 moves from the outside of the adsorption region R1 to the adsorption region R1, the atmosphere on the surface of the wafer W is replaced with the source gas from the N2 gas, the concentration of the source gas on the surface of the wafer W increases, and the source gas is transferred to the wafer W. To be adsorbed. However, since the increase in the concentration of the source gas due to the substitution is suppressed in the region where the N2 gas reservoir 71 is formed compared to the region outside the N2 gas reservoir 71, the amount of the source gas adsorbed is small. Since the wafer W is rotating as described above, when the wafer W is positioned in the adsorption region R1, the location where the N2 gas reservoir 71 is formed at the peripheral portion of the wafer W or the location where it is formed relatively large is: Since the wafer W is different each time it is positioned in the adsorption region R1, the film thickness of the peripheral edge can be made smaller than the film thickness of the central part of the wafer W over the entire circumference of the wafer W. For example, in an etching process after film formation, an apparatus is used in which the etching rate at the center of the wafer W is higher than the etching rate at the periphery, and at the end of the etching process, the film is formed between the periphery and the center of the wafer W. When it is desired to increase the uniformity of the thickness, it is effective to form the recess 25 where H1> H2 as described above.

  FIG. 13 shows another configuration example of the film forming apparatus 1. The difference from the above-described film forming apparatus 1 shown in FIG. 1 will be described. A space 72 is provided along the rotation direction of the turntable 2 below the recess 31 in which the heater 33 of the container body 13 is provided. 72 includes a support ring 42 and a rotation driving unit 27 for rotation. A wall portion between the recess 31 and the space 72 is indicated by 73 in the figure. In addition, the space in the recess 31 and the space 72 are connected to the flow path 74 formed on the downstream side of the exhaust port 36 in the container body 13 via valves V1 and V2, respectively. The valves V1 and V2 are opened at an appropriate opening degree.

  In FIG. 13, the flow of N 2 gas supplied from the gas supply pipe 15 is indicated by arrows. A part of the N 2 gas supplied from the gas supply pipe 15 to the center of the back surface of the turntable 2 flows to the exhaust port 36 along the back surface of the turntable 2, together with each gas flowing from the surface of the turntable 2. Removed. The other part of the N2 gas flows into the recess 31 and the space 72 through the gap between the rotary shaft 26 and the shield 34 and the gap between the wall portion 73 and the rotary shaft 26, respectively. It flows into 74. Then, it is removed together with each gas flowing into the exhaust port 36.

  Thus, the inside of the recess 31 and the space 72 are purged by the N 2 gas supplied from the gas supply pipe 15. As a result, particles generated from the rotation drive unit 27 for rotation in the space 72 are removed from the flow path 74, and scattering to the surroundings is more reliably suppressed. Moreover, it can prevent that source gas and oxidizing gas adhere to the heater 33, and the said heater 33 deteriorates. In addition to the gas supply pipe 15, a supply pipe for supplying N 2 gas may be provided in the recess 31 and the space 72.

  In the above example, the gas nozzle 51 supplies the ALD source gas. However, a film forming gas for film formation is supplied by CVD (Chemical Vapor Deposition), and the wafer is supplied to the region where the film forming gas is supplied. The orientation may be changed by the rotation of the wafer W each time W moves. That is, it is good also as an apparatus structure in which neither an oxidizing gas nozzle nor a separation gas nozzle is provided.

  FIG. 14 shows a film forming apparatus 8 as still another structural example of the film forming apparatus, and FIG. 15 shows a perspective view of the turntable 2 of the film forming apparatus 8. The film forming apparatus 8 will be described focusing on differences from the film forming apparatus 1. The rotation shaft 26 of the wafer holder 24 in the turntable 2 of the film forming apparatus 8 is provided so as to penetrate the support ring 42 and the magnetic seal unit 20 in the vertical direction. In the space 72 described with reference to FIG. 13, a magnetic gear 81, which is a first rotating body formed in a horizontal disk shape, is connected to the lower end of the rotating shaft 26. The magnetic gear 81 is composed of a plurality of magnets arranged along a circumferential direction that is the rotation direction thereof, and each magnet is arranged such that N poles and S poles are alternately positioned in the circumferential direction. The rotation shaft 26 rotates around the axis by the rotation of the magnetic gear 81.

  Further, a magnetic gear 82 that is a horizontal disk-shaped second rotating body is provided below the magnetic gear 81 in the space 72. The magnetic gear 82 is constituted by a plurality of magnets, for example, like the magnetic gear 81 except that the size and the number of magnetic poles are different. As will be described later, the center of the magnetic gear 82 is located closer to the peripheral edge of the rotary table 2 than the center of the magnetic gear 81 so that the magnetic gear 81 can be rotated by the magnetic gear 82. The magnetic gear 82 is connected to a rotation drive unit 84 provided on the bottom 13 of the film forming apparatus 8 via a rotation shaft 83. The rotation drive unit 84 rotates the magnetic gear 82 via the rotation shaft 83.

  Further, the rotation drive unit 84 includes a magnetic seal unit 85 and a motor (not shown). The magnetic seal unit 85 includes a bearing of the rotary shaft 83 and a magnetic seal that seals a gap around the rotary shaft 83, and suppresses particles generated from the bearing from being scattered in the space 72 that is a vacuum atmosphere. It is configured to be able to. Specifically, for example, the lubricant used for the bearing can be prevented from scattering into the space 72. The magnetic seal unit 85 also has a role of partitioning the vacuum atmosphere in the space 72 and the air atmosphere outside the vacuum vessel 11. In the film forming apparatus 8, as described with reference to FIG. 13, the N 2 gas from the gas nozzle 15 flows into the recess 31 and the space 72 and can be purged. Similarly to the film forming apparatus 1, a gas flow path 47 to which N 2 gas is supplied from the gas nozzle 48 is opened in the space 72, and the inside of the space 72 can be purged with the N 2 gas.

  The magnetic gear 81 revolves with the revolution of the wafer holder 24, and passes above the rotating magnetic gear 82 so that the peripheral edge thereof overlaps the peripheral edge of the magnetic gear 82. Thus, while the peripheral edge of the magnetic gear 81 and the peripheral edge of the magnetic gear 82 overlap, the magnetic gear 81 is rotated at a rotational speed corresponding to the rotational speed of the magnetic gear 82 by the magnetic force acting between the magnetic gear 81 and the magnetic gear 82. Rotates without contact with the magnetic gear 82. The wafer holder 24 is rotated by the rotation of the magnetic gear 81, and the wafer W is rotated. That is, in the film forming apparatus 8, the rotation of the wafer W is limitedly performed while the magnetic gear 82 overlaps the magnetic gear 81, so that the rotation of the wafer W is intermittently performed during the revolution. In this example, the sizes of the magnetic gears 81 and 82 and the number of magnetic poles are set so that the rotational speed of the magnetic gear 81 is smaller than the rotational speed of the magnetic gear 82.

  In the film forming apparatus 8, for example, as in the film forming apparatus 1, the operator selects a recipe (target film thickness T and rotation speed V of the turntable 2), cycle rate R, and number of rotations N from the setting unit 101. Then, the rotation speed A (rpm) of the wafer is calculated. And the rotation speed of the motor which comprises the rotation drive part 84 which rotates the magnetic gear 82 is controlled so that it may become the calculated autorotation speed.

  16 to 18 are schematic diagrams showing how the wafer W rotates and revolves during the film forming process. In these schematic diagrams, the wafers W are indicated by W1 to W5 as in FIGS. 7 to 10, and the directions of the wafers W1 to W5 are indicated by arrows A1 to A5. During the film forming process, each gas is supplied as described in the film forming apparatus 1. Then, the rotary table 2 rotates at the rotation speed set by the operator as described above, and the wafer W revolves. Along with this revolution, the motor of the rotation drive unit 84 rotates at the rotation speed calculated based on the rotation speed of the turntable 2 as described above, thereby rotating the magnetic gear 82 (FIG. 16).

  When, for example, the magnetic gear 81 connected to the wafer holder 24 holding the wafer W1 moves from the upstream side in the rotational direction to the upper side of the magnetic gear 82 by the rotation of the rotary table 2, the magnetic gear 81 is positioned so as to overlap the magnetic gear 82. The rotation of the magnetic gear 81 is started by the magnetic force between the gears 81 and 82, and the wafer W1 rotates (FIG. 17). When the rotation table 2 continues to rotate and the magnetic gear 81 moves downstream in the rotation direction with respect to the magnetic gear 82, the magnetic force is weakened and the rotation of the wafer W1 is stopped. Since the rotation speed of the wafer W is calculated based on the rotation speed of the turntable 2 as described above, the direction of the wafer W1 when the rotation is stopped is different from the direction when the rotation starts. With the orientation changed in this way, the wafer W1 moves to the suction region R1 by revolution. The amount of change in this direction follows the rotation speed of the wafer W calculated as described above.

  Further, the revolution is continued, and whenever the magnetic gear 81 moves onto the magnetic gear 82, the wafer W1 rotates, its direction is changed as described above, and it moves to the attracting region R1. Similarly to the wafer W1, the orientation of the wafers W2 to W5 is changed by rotation each time it revolves once and moves to the suction region R1. Accordingly, in the film forming apparatus 8 as well, the film thickness uniformity in the circumferential direction of the wafer W can be increased as in the film forming apparatus 1. Further, in this film forming apparatus 8, it is not necessary to provide a plurality of rotation driving units 84 for rotating the wafers W1 to W5, so that the manufacturing cost of the apparatus can be suppressed. Further, since the magnetic gears 81 and 82 for transmitting the power of the rotational drive unit 84 to the wafer holder 24 are not in contact with each other, generation of particles can be suppressed. Even if particles are generated between the rotation shaft 26 for rotating the wafer W and the support ring 42 that supports the rotation shaft 26, the rotation shaft 24 and the support ring 42 are described with reference to FIG. In addition, since it is provided in the space 72 purged by the N 2 gas during the film forming process, the particles can be prevented from adhering to the wafer W.

  In the film forming apparatus 8, only one magnetic gear 82 and one rotation drive unit 84 are provided. However, a plurality of these may be provided, and the wafer W may rotate at a plurality of locations while the wafer W revolves once. Further, the magnetic gears 81 and 82 are arranged in a lateral direction as shown in FIG. 19, and the magnetic gear 81 close to the magnetic gear 82 is selectively rotated by revolution, whereby each wafer W rotates intermittently. You may make it do. In the example shown in FIG. 19, the magnetic gears 81 and 82 are shown in a cylindrical shape, but the magnets are arranged in the same manner as the disk-like magnetic gears 81 and 82 shown in FIGS. 14 and 15. Composed. In the above example, both of the magnetic gears 81 and 82 are made of magnets, but one of them may be made of a magnetic material that is not a magnet. For example, the magnetic gear 82 is composed of a magnet, and the magnetic gear 81 is composed of a magnetic material such as iron. Accordingly, as in the above example, when the magnetic gear 81 is approaching the magnetic gear 82, the magnetic gear 81 may be rotated following the rotation of the magnetic gear 82 to rotate the wafer W. . The magnetic gear 81 may be a magnetic material, and the magnetic gear 82 may be a magnet.

(Evaluation test)
An evaluation test related to the present invention will be described. In the description of each evaluation test, for the wafer W placed on the wafer holder 24, the diameter of the wafer W that coincides with the diameter of the turntable 2 at the start of the film forming process is described as a Y line. Accordingly, the Y line is a region indicated by arrows A1 to A5 in FIG. And the diameter of the wafer W orthogonal to this Y line is described as X line.

Evaluation test 1
A test was conducted to examine the change in film thickness distribution due to rotation of the wafer W having a diameter of 300 mm. As the evaluation test 1-1, a simulation for forming a film without rotating the wafer W in the film forming apparatus 1 was performed. In addition, as evaluation test 1-2, a simulation was performed in which film formation was performed under the same conditions as in evaluation test 1-1 except that the wafer W was rotated. However, in this evaluation test 1-2, unlike the embodiment, the wafer W is set to rotate by 180 ° from the start of the film formation process to the end of the film formation process. Further, a test similar to the evaluation test 1-2 was performed as the evaluation test 1-3, but the wafer W was set to rotate by 45 ° as a difference. Further, as an evaluation test 1-4, a simulation was performed under the same conditions as the evaluation tests 1-1 to 1-3 except that the wafer W was set to rotate an integer number of times as in the embodiment. In each of the evaluation tests 1-1 to 1-4, the film thickness distribution in the plane of the wafer W was measured.

  The upper and lower stages of FIG. 20 schematically show the in-plane film thickness distributions of the evaluation tests 1-1 and 1-2, respectively. The upper and lower stages of FIG. 21 show the evaluation tests 1-3 and 1-4, respectively. 2 schematically shows the in-plane film thickness distribution of the wafer W. The actually obtained test results are computer graphics in which a color corresponding to the film thickness is attached to the surface of the wafer W. In FIG. 20 and FIG. Each of the regions in which is a predetermined range is surrounded by contour lines and shown with a pattern.

  Moreover, the upper part of FIG. 22 is a graph showing the film thickness distribution of each Y line of the evaluation tests 1-1 and 1-4, and the lower part is a film thickness distribution of each X line of the evaluation tests 1-1 and 1-4. It is a graph which shows. The horizontal axis of each graph indicates the distance (unit: mm) from one end of the wafer W. One end of the wafer W in the Y-line graph is the end on the central axis side of the turntable 2. The vertical axis of each graph represents the film thickness (unit: nm). The upper part of FIG. 23 is a graph showing the film thickness distribution of each Y line of evaluation tests 1-2 and 1-3, and the lower part is the film thickness distribution of each X line of evaluation tests 1-2 and 1-3. It is a graph to show.

  20 and 21, the uniformity of the film thickness distribution in the circumferential direction of the wafer W is increased by rotating the wafer W, and in the evaluation test 1-4 rotated by an integer number of times, the circumferential direction of the wafer W is rotated. It can be seen that the uniformity of is extremely high. Moreover, when it sees about each graph, the big difference is not seen by the film thickness distribution of X line by the evaluation tests 1-1 to 1-4. Regarding the film thickness distribution of the Y line, a slight difference in film thickness between one end and the other end of the Y line seen in the evaluation test 1-1 is small in the evaluation tests 1-2 and 1-3. It is almost lost in Evaluation Test 1-4. Therefore, it can be seen from each graph that the film thickness distribution in the circumferential direction of the wafer W is highly uniform.

Further, for each of the evaluation tests 1-1 to 1-4, it was calculated from the film thickness measured at 49 positions in the plane of the wafer W including the measurement positions on the X line and the Y line. Table 1 below shows the average value of the film thickness, the maximum value of the film thickness, the minimum value of the film thickness, the difference between the maximum value and the minimum value of the film thickness, and WinW which is an index representing the in-plane uniformity. WinW is ± {(maximum value of film thickness−minimum value of film thickness) / (average value of film thickness)} / 2 × 100 (%), and Table 1 shows the absolute value. The smaller the absolute value, the higher the in-plane uniformity. By comparing the WinW of the evaluation tests 1-1 to 1-4 and rotating the wafer W, the uniformity of the film thickness is increased not only in the circumferential direction but also in the entire surface of the wafer W, and the evaluation It can be seen that Test 1-4 has the highest uniformity of film thickness across the entire surface. Therefore, from this evaluation test 1, it is understood that rotating the wafer W as described in the embodiment is effective for increasing the uniformity of the film thickness in the surface of the wafer W, and the number of rotations. It can be seen that it is particularly effective to use an integer.

Evaluation test 2
As the evaluation test 2, a test for examining the influence of the height H1 of the side wall in the recess 25 of the wafer holder 24 described with reference to FIG. In the evaluation test 2-1, the height H1 of the side wall is set to 1.0 mm which is the same as the thickness H2 of the wafer W, and the film formation by the film formation apparatus 1 is performed without rotating the wafer W as in the evaluation test 1-1. A simulation of processing was performed. The rotation speed of the turntable 2 was set to 120 rpm. Further, as evaluation test 2-2, simulation was performed under the same conditions as in evaluation test 2-1, except that the wafer W was rotated during the revolution of the wafer W, and the film thickness of each part of the wafer W was measured. . As evaluation tests 2-3 and 2-4, simulation was performed under the same conditions as evaluation tests 2-1 and 2-2 except that the height H1 of the side wall was set to 1.8 mm as shown in FIG. It was. About the evaluation tests 2-1 to 2-4, the film thickness of each part of the formed wafer W was measured.

  The upper and lower sections of FIG. 24 show images obtained for the film thickness distributions of the wafers W in the evaluation tests 2-1 and 2-2, respectively, as in the case of the evaluation test 1, as a schematic diagram. The upper part and the lower part of FIG. 25 show schematic views of the wafer W for the evaluation tests 2-3 and 2-4, as in FIG. The upper graph of FIG. 26 shows the film thickness distribution of the X line of evaluation tests 2-1 and 2-2, and the lower graph of FIG. 26 shows the film thickness of the Y line of evaluation tests 2-1 and 2-2. Distribution is shown. The upper graph in FIG. 27 shows the film thickness distribution in the X line of evaluation tests 2-3 and 2-4, and the lower graph in FIG. 27 shows the film thickness distribution in the Y line in evaluation tests 2-3 and 2-4. Show. The horizontal axis of each graph in FIGS. 26 and 27 indicates the distance from one end of the wafer W, similarly to the horizontal axis of each graph of the evaluation test 1. FIG. However, the vertical axis represents the deposition rate (unit: nm / min) instead of the film thickness.

  24 to 27, it can be seen that the uniformity of the film thickness in the circumferential direction of the wafer W is increased by rotating the wafer W regardless of the height H1 of the side wall. . Further, regarding the film thickness at both ends of the X line and the Y line, the evaluation test 2-2 in which the side wall height H1 is about 5.5 mm in the side wall height H1 and the side wall height H1 is 1.8 mm. 4, it is about 5.0 mm, and it can be seen that the evaluation test 2-4 is lower. Therefore, in order to reduce the film thickness of the peripheral portion of the wafer W, the height H1 of the side wall is made larger than the thickness of the wafer W, and a step is formed between the recess 25 and the surface of the wafer W as described in the embodiment. It is effective to form

Similarly to evaluation test 1, for evaluation tests 2-1 to 2-4, the average value of the film thickness, the maximum value of the film thickness, and the minimum value of the film thickness calculated from the film thickness of each measurement location on the wafer W Table 2 below shows the difference between the maximum value and the minimum value of the film thickness, and WinW. It can be seen from the comparison of the test results of the evaluation tests 2-1 and 2-2 and the comparison of the test results of the evaluation tests 2-3 and 2-4 that the WinW is reduced by rotating the wafer W. Accordingly, it can be seen that by rotating the wafer W, the uniformity of the film thickness can be enhanced not only in the circumferential direction but also in the entire in-plane of the wafer W.

Evaluation test 3
The influence of the recess 25 of the wafer holder 24 on the film thickness distribution was examined. In this evaluation test 3, a simulation for performing a film forming process without rotating the wafer W was performed, and the film thickness of each part of the wafer W was measured. In evaluation tests 3-1 to 3-3, the height H1 of the side wall of the recess 25 is set to 1.0 mm, and in evaluation tests 3-4 to 3-6, the height H1 of the side wall of the recess 25 is set to 1.8 mm. did. In evaluation tests 3-1 and 3-4, the rotational speed of the rotary table 2 is 20 rpm, in evaluation tests 3-2 and 3-5, the rotational speed of the rotary table 2 is 60 rpm, and in the evaluation tests 3-3 and 3-6, the rotary table. The rotational speed of 2 was set to 120 rpm. During the film formation process, the temperature of the wafer W is 600 ° C., the pressure in the vacuum vessel 11 is 1.8 Torr (240.0 Pa), the flow rate of the source gas is 200 sccm (0.34 Pa · m ³ / sec), and an oxidizing gas. The flow rate of O 3 gas was set to 6 slm (1.01 Pa · m ³ / sec), the flow rate of N 2 gas from the central region forming portion C was set to 0 sccm, and the film forming time was set to 10 minutes.

  In the upper, middle, and lower stages of FIG. 28, images obtained for the film thickness distributions of the wafers W in the evaluation tests 3-1, 3-2, and 3-3 are shown in the same manner as FIGS. 20 and 21 in the evaluation test 1, respectively. It is shown as a schematic diagram. Similarly to FIG. 28, the upper, middle, and lower stages in FIG. 29 show images obtained for the film thickness distribution of the wafer W in the evaluation tests 3-1, 3-2, and 3-3 as schematic diagrams. . Further, the upper and lower graphs of FIG. 30 show the film thickness distributions of the X line and the Y line in the evaluation tests 3-2 to 3-6, respectively. The horizontal axis and vertical axis of each graph in FIG. 30 indicate the distance from one end of the wafer W and the deposition rate, respectively, as in the horizontal axis and vertical axis of each graph of FIG. 26 and FIG. Since the film thickness distributions of the X line and Y line of the evaluation test 3-1 are substantially the same as the film thickness distributions of the X line and Y line of the evaluation test 3-4, the display in the graph is omitted. ing.

  From the graphs and schematic diagrams, in the evaluation tests 3-5 and 3-6 in which the rotation speed of the turntable 2 is relatively high and the height H1 of the side wall of the recess 25 is 1.8 mm, It can be seen that a part of the film thickness is smaller than the film thickness of other regions. By rotating the wafer W, the gradient of the film thickness distribution is made uniform in the circumferential direction of the wafer W. Thus, after setting the height H1 of the side wall of the recess, the wafer W is rotated and the rotation table 2 is rotated. It is presumed that the film thickness at the peripheral edge can be reduced over the entire circumference of the wafer W by making the rotational speed relatively high.

W Wafer 1 Film forming apparatus 11 Vacuum container 2 Revolving table 22 Revolving rotary drive unit 24 Wafer holder 25 Recess 26 Revolving shaft 27 Rotating rotary drive unit 33 Heater 41 Support column 51 Source gas supply nozzle 100 Control unit 101 Setting unit

Claims (13)

A film forming apparatus for obtaining a thin film by supplying a processing gas to a substrate,
A rotary table that is placed in a vacuum vessel and placed on a placement area provided on one side thereof to revolve the substrate,
A rotation mechanism for rotating the placement area so that the substrate rotates,
A process gas supply mechanism for supplying the process gas to a gas supply region on one surface side of the turntable and performing film formation on the substrate that repeatedly passes through the gas supply region by the revolution; and
The rotation speed of the substrate is calculated based on parameters including the rotation speed of the turntable so that the orientation of the substrate changes every time the substrate is positioned in the gas supply region, and the substrate is moved at the calculated rotation speed. A control unit that outputs a control signal so as to rotate,
A film forming apparatus comprising:   The film formation according to claim 1, wherein the calculation includes a multiplication of a rotation speed of the turntable and a value obtained by dividing an increase in film thickness per rotation of the turntable by a target film thickness. apparatus. The calculation includes a multiplication of a rotation speed of the turntable, a value obtained by dividing an increase in film thickness per rotation of the turntable by a target film thickness, and a natural number N of 1 or more,
The film forming apparatus according to claim 2, further comprising a setting unit for an operator to set the natural number N. The rotation mechanism is provided on the other surface side of the rotary table, and includes a rotation shaft for rotation that revolves by rotation of the rotary table,
A support member provided on the other surface side of the rotary table to support the rotary shaft for rotation with respect to the rotary table;
The heater for heating the rotary table from the other surface side is provided along the rotation direction of the rotary table on the inner side and the outer side of the moving path of the rotary shaft for rotation and the support member, respectively. The film forming apparatus according to any one of 1 to 3. The support member connects the support column and the rotation mechanism on the lower side of the heater, and a support column provided on the other surface side of the rotation table away from the rotation shaft for rotation in the rotation direction of the rotation table. And a connecting portion for supporting the rotation mechanism with respect to the support,
The film forming apparatus according to claim 4, further comprising: A first rotating body made of a magnet or a magnetic body that revolves together with the mounting area and rotates the mounting area by rotation thereof;
The rotating mechanism includes a second rotating body made of a magnet or a magnetic body,
At least one of the first rotating body and the second rotating body is made of a magnet,
The first rotating body that revolves is intermittently rotated in a non-contact manner by a magnetic force between the first rotating body and the second rotating body. The film-forming apparatus as described in one. A reaction gas supply mechanism that supplies a reaction gas that reacts with the processing gas to a reaction gas supply region that is provided apart from the processing gas supply region in the circumferential direction of the turntable;
A separation gas supply unit for supplying a separation gas to a separation region provided between the reaction gas supply region and the processing gas supply region, and the mounting region is configured by a bottom surface of a recess, 7. The film forming apparatus according to claim 1, wherein the depth of the recess is greater than the thickness of the substrate.   8. The film forming apparatus according to claim 7, wherein the depth of the concave portion is 1.8 times the thickness of the substrate. A film forming method for obtaining a thin film by supplying a processing gas to a substrate,
A step of placing and revolving a substrate on a placement region provided on one side of a rotary table disposed in a vacuum vessel;
A step of rotating the placement region so that the substrate rotates by a rotation mechanism;
Supplying the processing gas to a gas supply region on one surface side of the turntable by a processing gas supply mechanism, and forming a film on a substrate that repeatedly passes through the gas supply region;
Calculating the rotation speed of the substrate based on parameters including the rotation speed of the turntable so that the orientation of the substrate changes each time the substrate is positioned in the gas supply region;
A process of rotating the substrate at the calculated rotation speed;
A film forming method comprising: The step of calculating the rotation speed of the substrate includes:
The film forming method according to claim 9, further comprising a step of multiplying the rotation speed of the turntable by a value obtained by dividing the amount of increase in film thickness per rotation of the turntable by the target film thickness. . The step of calculating the rotation speed of the substrate includes:
The calculation is performed by multiplying the rotation speed of the turntable, a value obtained by dividing the increase in film thickness per rotation of the turntable by the target film thickness, and a natural number N of 1 or more;
Setting the value of the natural number N;
The film forming method according to claim 10, comprising: The step of rotating the mounting area is as follows:
Revolving the first rotating body made of a magnet together with the placement area;
A step of intermittently rotating the first rotating body in a non-contact manner by a magnetic force acting between the second rotating body including the magnet and the second rotating body, which constitutes the rotating mechanism; and
Rotating the placement area by rotating the first rotating body;
The film forming method according to claim 9, further comprising: In a storage medium storing a computer program used in a film forming apparatus for supplying a processing gas to a substrate to obtain a thin film,
A storage medium, wherein the computer program includes steps so as to perform the film forming method according to any one of claims 9 to 12.

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